Studies of lens cataract will continue, first with detailed observations on the clinical condition and second to be followed by attempts to produce animal models of specific types of cataracts. The animal studies in turn will be utilized along with the techniques of autoradiography and electron microscopy to understand the mechanism of lens cataract formation. BIBLIOGRAPHIC REFERENCES: McDonals JE, FH Roy and C Hanna: After-Cataract of the rabbit: Autoradiography and electronmicroscopy. Ann. Ophthal. 6:37-50, 1974. Thomas AH and C Hanna: Electric cataracts III, Animal model. Arch Ophthal 91: 469-473, 1974.